Windows Update KB2670838 that has been recently made available is causing bugs on quite a big number of Windows7 machines, if not all. This Windows Update installs Windows8 graphics libraries and components and changes the way Windows7 handles graphics and/or graphics memory and this causes DC to crash.

At the moment there is only one way to get DC to run again and it is by de-installing this optional KB2670838 Windows update and than also hiding it to avoid an update at a later moment.